If Not for Yourself, Diet for the Planet

Dieting, like quitting smoking, requires motivation. Pet lovers have found it easier to stop smoking when they learn that second-hand smoke can harm their pets. Here’s an added motivation for overweight environmentalists. Lose weight, and you can help battle global warming. Researchers at the London School of Hygiene & Tropical Medicine have published an interesting analysis in the International Journal of Epidemiology.

Most countries in the world are experiencing an increase in the average body mass index (BMI) of their population. The researchers decided to estimate the impact of these increases on greenhouse gas emissions. They selected two hypothetical adult populations – one with a 40% obesity level (BMI 30 or higher) and one with a ‘normal’ adult population – with an obesity level of 3.5%. Then they estimated the food energy required to maintain the BMIs for each population. Additional energy needs were added for transporting (walking, and using autos and airplanes) the heavy and the lean populations.

Compared with the normal population, the one with 40% obese members would require 19% more food energy, and 12% more energy for transport needs. It’s estimated that a ‘normal’ population of 1 billion people would emit I giga-tonne (!,000 million tonnes) less carbon dioxide equivalents a year than 1 billion people from a 40% obese population.

As I said in the title to this post, if you won’t diet for yourself, diet for the planet. Our grandchildren will be grateful to you.